Light Emitting Diodes (LEDs) are a very energy efficient electronic lighting source. The first generation of LEDs emitted red light with a very small amount of illuminating power. However, modern LEDs can now generate light across the visible, ultraviolet, and infra-red wavelengths. Furthermore, modern LEDs can be provided with a significant amount of current such that LEDs can produce enough light to be used as illumination sources.
Driving LEDs is much more complex than driving a traditional incandescent light bulb. A traditional incandescent light bulb can be driven merely by putting the bulb directly into a traditional household AC circuit. LEDs require carefully controlled DC power. Furthermore, many individual LEDs must be powered to provide the same light output as a single incandescent light bulb. Thus, designing efficient LED power circuits is important for the success of LED lighting. It would therefore be desirable to create efficient power supply and driving circuitry for LED based lighting systems.